U.S. patent number 3,919,920 [Application Number 05/402,738] was granted by the patent office on 1975-11-18 for machine for making obtunded key profile.
This patent grant is currently assigned to Schlage Lock Company. Invention is credited to Ernest L. Schlage.
United States Patent |
3,919,920 |
Schlage |
November 18, 1975 |
Machine for making obtunded key profile
Abstract
An obtunded key profile is provided in a lock key having a shank
extending parallel to a straight reference line. The key has a
plurality of reference surfaces spaced apart longitudinally in the
direction of the line according to a predetermined pattern and
spaced transversely away from the line also according to a
predetermined pattern. An adjacent pair of the reference surfaces
is joined by a connecting surface devoid of a sharp peak. A machine
for providing an obtunded key profile in a lock key having a shank
includes a base on which a pillow block is mounted. A stylus
projects from the pillow block. A shaft is rotatable in the pillow
block and carries a key cutter. Mounted to move on the base in two
normal directions in a plane containing the shaft axis is a
carriage having a key blank holder. A key blank in the holder is
cut by the cutter according to contact with the stylus of depth
gauge rods settably secured on the carriage. The stylus, the depth
gauge rods, or both, are devoid of sharp peaks.
Inventors: |
Schlage; Ernest L. (Burlingame,
CA) |
Assignee: |
Schlage Lock Company (San
Francisco, CA)
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Family
ID: |
26942255 |
Appl.
No.: |
05/402,738 |
Filed: |
October 2, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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252344 |
May 10, 1972 |
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Current U.S.
Class: |
409/82 |
Current CPC
Class: |
B23C
3/355 (20130101); Y10T 409/301008 (20150115) |
Current International
Class: |
B23C
3/00 (20060101); B23C 3/35 (20060101); B23C
001/16 () |
Field of
Search: |
;90/13.05 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yost; Frank T.
Assistant Examiner: Bilinsky; Z. R.
Attorney, Agent or Firm: Lothrop & West
Parent Case Text
This is a division application Ser. No. 252,344, filed, May 10,
1972 and now abandoned.
Claims
What is claimed is:
1. A machine for cutting an obtunded key from a key blank,
comprising a base, means supporting a key cutter for rotation on
said base about an axis, a stylus fixed on said base in a plane
parallel to said axis and having a longitudinal face and inclined
side faces tranverse to said plane, a carriage, means mounting said
carriage on said base for universal movement in a plane to said
axis, a key blank holder on said carriage adjacent said key cutter,
a plurality of elongated depth gauge rods having end surfaces and
arranged in parallel, side by side relation with said rods
extending toward said axis and adjacent said stylus said stylus and
said rods being coplanar, and means mounting said depth gauge rods
for individual adjustment on said carriage toward and away from
said axis whereby movement of said carriage toward and along said
axis causes said end surfaces of the gauge rods to engage and move
along said longitudinal and inclined side faces of said stylus and
simultaneously causes said key cutter to cut an obtunded key from a
key blank held in said key blank holder.
2. A machine as in claim 1 in which said stylus is relatively wide
and said rods are positioned so that said stylus can engage two of
said rods simultaneously.
Description
Many key blanks for use in locksets having tumblers are serrated,
dentated or toothed since they are provided along at least one edge
with notches defined by truncated V-shaped surface. The
intersection of the surfaces near the edge of the key affords sharp
peaks. These peaks produce numerous operational difficulties.
It is therefore an object of my invention to provide an improved
configuration of the serrated, dentated or toothed portion of a
lock cylinder key.
It is another object of my invention to provide an improved,
obtunded configuration for key blades or shanks of various shapes
and cross-sections, such as flat, corrugated, rectangular,
"T"-shaped, "V"-shaped, dendritic or cruciform.
It is another object of my invention to provide an improved,
obtunded configuration for keys notched along one edge or along two
edges, as in reversible keys.
A further object of my invention is to provide an improved,
obtunded configuration for keys designed for use in pin tumbler
cylinders or wafer tumbler cylinders, whether the pin tumblers are
circular cylindrical or are other than circular in cross-section,
such as square, and whether the pin ends have conical ends,
bullet-nose ends or wedge-shaped ends, or are supplemented by
bearing balls, and whether the wafer tumblers have dogging
projections extending from one or both ends.
A further object of the invention is to provide an improved,
obtunded configuration for keys of any length, particularly keys
for four, five, six or seven rows of tumblers in the cylinder.
An additional object of the invention is to provide an improved,
obtunded configuration to prevent the key peaks from producing
oscillations of the tumbler pins in an excessive amout during key
insertion and retraction, thereby causing pin wear, spring fatigue
and high key camming forces.
A still further object of the invention is to provide an improved,
obtunded configuration to prevent the key peaks from promoting
improper opening by false or bogus keys, either by partial key
insertion, by a slow insertion or retraction of the key, or by a
rapid insertion and retraction of the key causing the tumblers to
bounce in their chambers similar to the effect caused by raking
picks or lock picking vibrators.
An additional object of the invention is to provide a machine for
cutting a key to meet the various objects of the invention.
A still further object of the invention is to provide a machine for
cutting keys pursuant to the invention and that can be adapted to
cut keys automatically to meet the various objects of the
invention.
Other objects together with the foregoing are attained in the
embodiments of the invention described in the accompanying
description and illustrated in the accompanying drawings, in
which:
FIG. 1 is an elevation of one form of an obtunded key pursuant to
my invention;
FIG. 2 is an elevation of another form of contour of an obtunded
key pursuant to my invention;
FIG. 3 is an elevation of a further form of contour of an obtunded
key pursuant to my invention;
FIG. 4 is an elevation of still further form of contour of an
obtunded key pursuant to my invention;
FIG. 5 is an elevation of an additional form of contour of an
obtunded key pursuant to my invention;
FIG. 6 is a plan, partly diagrammatic, of my machine for forming an
obtunded key; and
FIG. 7 is a plan showing a detail of a modification of my machine
as shown in FIG. 6.
As an example of a key blank configured pursuant to the invention,
there is illustrated in FIG. 1 a generally flat, stiff blank having
a shank 6 and having a bow portion 7 for manual operation, the bow
being broken away to reduce the size of the figure. The shank 6
along one edge 8 is initially substantially rectilinear. This edge
or a substantially coincident, imaginary, parallel line 9 can be
utilized as a reference or datum line. At its end opposite the bow
7 the key shank is provided with a rounded nose 11 merging with
inclined sides 12 and 13 to assist the key in entering the lock
mechanism. The key, in this instance, is preferably designed for
use in a lock having five columns of tumblers to be actuated, each
of the columns being represented by a respective one of five broken
lines 15, 16, 17, 18 and 19. These lines are appropriately spaced
in a longitudinal direction from one of two opposite, transverse
datum surfaces 21 and 22 at the junction of the key shank with the
key bow. The lines 15 to 19, inclusive, thus are arranged according
to a predetermined pattern and can be considered to denote stations
spaced apart longitudinally of the key in set or predetermined
amounts to serve a particular lock.
To meet the needs of the lock with which the key is to be utilized
it is also desired to provide at each of the stations or locations
15 to 19, inclusive, a datum surface that is disposed a
predetermined distance and according to a predetermined pattern
from either the imaginary, straight reference line 9 or from the
edge 8, if that happens to be an appropriate reference. The pattern
of the datum surfaces is often indicated on the key bow by a series
of numerals 24, the exemplary number in this instance being
"35487". This indicates that at the station or line 15, for
example, there is a datum surface 26 spaced from the imaginary line
9 a lateral or transverse distance of three units. Comparably, at
the line or station 16 there is provided a datum surface 27 spaced
from the line 9 a transverse or lateral distance of five units, and
at the location 17 there is provided a datum surface 28 spaced from
the line 9 a lateral distance of four units. At the location or
station 18 the datum surface 29 is laterally spaced from the datum
line 9 a distance of eight units and, finally, at the location 19
the datum surface 30 is spaced transversely from the datum line 9 a
distance of seven units. Each of the datum surfaces 26 to 30,
inclusive, is intended to abut a tumbler pin or wafer in the lock.
For that reason, and depending upon the shape of the coacting
parts, the surface, such as 26, can be a mathematical line
extending across the thickness of the key and constituting a point
when seen in FIG. 1. However, the usual key followers or pins have
some dimension larger than that of a point, and hence it is
preferred to have the surface 26 extend in a direction parallel to
the imaginary line 9 for a preselected longitudinal distance; for
example, 0.031 inches.
To establish the flat datum surface 26 in the desired location, it
is customary to shape the key blank by a cutter bounded in part by
a pair of converging cutting surfaces indicated by the broken lines
32 and 33. These surfaces, in one instance, are disposed at one
hundred degrees included angle and instead of converging to a point
are truncated to afford the surface width of 0.031 inches in a
direction normal to the location line 15 and parallel to the line
9. When the cutter operates in coincidence with the line 16, it
produces a similar, flat datum surface 27. The locations of the
comparable cutter lines 32 and 33a result in the formation of a
peak 34, because the lines 33a and 32 intersect at a sharp point.
Similarly, when the surface 28 is made, the cutter lines 32a and
33b produce a similar peak 36. Additional peaks such as 37, 38 and
39 are comparably formed. The cutter in each instance is moved into
its longitudinal position symmetrical with the location lines 15,
16, 17, 18 and 19 and ther is moved from the datum line 9 laterally
or transversely into its final cutting position. This produces the
described peaks.
Pursuant to my invention and as illustrated in FIG. 1, the cutter
is differently operated to produce my obtunded or obtruncated key
profile. If the cutter is the usual rotary cutter rotatable about
an axis parallel to the imaginary line 9, the cutter is moved into
symmetry with the line 15 and then is moved laterally to produce
the truncated "V" notch with a first surface 26. Instead of being
transversely withdrawn and then moved longitudinally according to
rectangular coordinates to the next location 16, the rotary cutter
is moved as soon as the surface 26 has been formed. This provides a
rectilinear, longitudinal surface 41 that is, in effect, a
continuation of the surface 26. When the cutter is indexed and
moved into the position of the line 16 to produce the surface 27,
no peak 34 results, as such peak has been obtunded.
In a comparable fashion, when the surface 27 has been provided, the
cutter is laterally backed off even with the surface 28 and is then
moved longitudinally to provide side surfaces 42 and 43, in the
process also establishing the surface 28. The peaks 36 and 37 are
obtunded. Finally, after the surface 29 has been established, the
cutter is moved to the transverse location of the surface 30 and
then is moved longitudinally to provide not only the surface 30 but
also the surfaces 44 and 46, virtual extensions of the surface 30,
and thereby obtunding the peaks 38 and 39. By this rectangular
profile method all of the usual peaks are eliminated from the key
profile.
Special consideration must be given to keys with a continually
descending profile; for example, 34578. When fully obtunded such a
key has no peaks to be caught behind pins blocked when the cylinder
plug is turned. Hence the key can always be withdrawn even though
the plug is not in the customary position for key withdrawal. Keys
of this descending or downhill character make up but a small part
of the total possible key combinations and so, in most cases, can
be eliminated entirely. If this is not feasible, at least one
uphill surface (not necessarily sharply peaked) can be provided to
preclude improper withdrawal of keys having a downhill profile.
As shown in FIG. 2, the key shank 6 is the same as before, having
the same code number 24, and having the same surfaces 26, 27, 28,
29 and 30. The key is formed by a cutter represented by the broken
lines 32 and 33, as before. The cutter moves longitudinally to the
first station 15 and moves laterally to the desired depth for the
suface 26. The cutter then moves longitudinally just to the edge of
or clear of the flat surface 26 and then moves to the surface 27
symmetrical with the station 16 by moving on a path 51 not parallel
to but inclined with respect to the line 9. The path 51 is a
straight line at the particular angle making a minimum distance
between the closest edges of the surfaces 26 and 27. That is, the
surface 51 is the shortest path between the adjacent edges of the
two surfaces 26 and 27. The cutter is moved to the next station 17
on an inclined path 52 generating an edge of minimum extent between
the edges of the flat surface 27 and the beginning of the next
adjacent flat surface 28. In moving to the surface 29, the cutter
does so along a minimum path 53 at a relatively steep inclination
between the edges of the flats. From the surface 29 the cutter
moves along a minimum, inclined path 54 between the flat edges and,
finally, from the surface 30 the cutter moves along a short,
peakless path 56 to the angle surface 12 of the key shank. Each of
the surfaces 51, 52, 53, 54 and 56 obtunds the otherwise present
key peaks 34, 36, 37, 38 and 39.
As particularly shown in FIG. 3, the key shank 6 is as before with
the same configuration numeral 24 and is established by the same
cutter represented by the broken lines 32 and 33 with respect to
the same datum line 9. At the station 15 the cutter is operated
just as before to provide the surface 26, but in moving from
station 15 to station 16 in order to provide the surface 27 the
cutter moves in an arbitrary, curved path 57. The path contour is
selected to afford the desired movement of the following tumbler
during key insertion or retraction, to provide adequate material
between the surfaces 26 and 27 and to afford whatever accelerations
between stations are deemed advantageous. Similarly, the cutter
moves from the surface 27 to the station 17 to form the surface 28
and thence to the station 18 to form the surface 29, then to the
station 19 to form the surface 30, and finally to the end surface
12. In each instance the resulting curve surfaces 57, 58, 59, 60
and 61, although arbitrary, leave the key devoid of otherwise
present peaks such as 34, 36, 37, 38 and 39.
As particularly shown in FIG. 4, the key shank 6 therein has the
same configuration index 24 as before and has the same datum
surfaces 26, 27, 28, 29 and 30 disposed at the same respective
stations 15, 16, 17, 18 and 19. Furthermore, the same cutter
indicated by the broken lines 32 and 33 is employed. In this
instance the cutter, although moving parallel to the datum line 9,
does not move at levels coincident with the surfaces 26, 27, 28, 29
and 30. Rather, the cutter, although moving according to
rectangular coordinates, travels longitudinally at arbitrary levels
so that from the surface 26 to the surface 27, for example, there
are three surfaces 66, 67 and 68 provided. The surface 67 is
parallel to the imaginary line 9 and obtunds the otherwise
resulting peak 34. Quite similarly, the peaks 36, 37, 38 and 39 are
obtunded by the longitudinal surfaces 69, 70, 71 and 72. In this
instance while the peaks have been obtunded, material has not been
removed to as great an extent as previously described.
In a fashion somewhat comparable to the showings in FIGS. 3 and 4,
the key shank 6, in FIG. 5 has the same datum surface configuration
indicated by the numeral 24, but in this instance the surface 26 at
the station 15 is joined to the surface 27 at the station 16 by a
circularly arcuate surface 73 which obtunds the otherwise existing
peak 34. Similarly, surfaces 74, 75, 76 and 77 obtund the otherwise
occurring peaks 36, 37, 38 and 39.
Various obtunded key profiles can be produced in various different
ways and with various different mechanisms, but I have particularly
provided a machine, as shown in FIGS. 6 and 7, especially for this
purpose.
The machine includes a stationary base frame 81 on which is mounted
a pillow block 82 carrying a power driven, rotary shaft 83 equipped
with a rotatable milling cutter 84. Preferably, the cutter edges
are inclined at a 100.degree. included angle as indicated by the
dotted lines 32 and 33. These cutting edges do not intersect, but
rather merge with a central cutting edge 88 parallel to the
longitudinal axis 89 of the shaft 83.
Designed to move in a plane parallel to and on the base frame 81 is
a primary slide 91 having a pair of longitudinal slots 92 and 93
therein parallel to the axis 89. Guide pins 94 and 96 project from
the base through the slots and have retainers 97 thereon. The
primary slide 91 can move only in a longitudinal direction in one
plane. Mounted on the primary slide 91 is a secondary slide 98 also
movable in a parallel plane but only in a normal or transverse
direction at right angles to the axis 89. The secondary slide 98 is
guided by pins 99 and 101 fixed thereon and passing through
transversely extending slots 103 and 104 in the primary slide 91.
There are appropriate retainers (not shown) on the pins. The
secondary slide 98 is confined to planar, transverse movement with
respect to the primary slide 91.
The secondary slide 98 in the vicinity of the cutter 84 is provided
with a key blank vise 106. This includes an extension 107 of the
secondary slide 98 and a plate 108 movable toward and away
therefrom under the influence of a threaded shaft 109 rotated by a
vise handle 111. A key bland 112 can be introduced between the
secondary slide extension 107 and the plate 108 with its edge 113
(or the datum line 9) parallel to the axis 89. The blank is clamped
in position with a datum surface 22 of the key blank abutting the
near one of a pair of suitable stops 114 and 115 projecting
upwardly from the secondary slide 98 through apertures 116 and 117
in the vise plate 108, so that the key is properly positioned and
secured. A handle 118 on the secondary slide 98 permits the
operator to move the key blank longitudinally, transversely and in
any single plane combination of longitudinal and transverse paths
with respect to the cutter 84, so that any configuration can be
given to the edge 113 of the blank.
In accordance with the invention and to provide any of the desired
obtunded key profiles, I preferably lodge in the secondary carriage
98 a plurality of depth gauge rods 121, 122, 123, 124 and 125
corresponding in number and in longitudinal stations to the lines
15 to 19, inclusive. Each depth gauge rod is provided with a
rectangular end 127 and likewise carries a plurality of indicia 128
corresponding to the various possible depths or transverse
distances from the line 9 of the key profile intended or of the
datum surfaces. There is a stop block 129 on the secondary carriage
98. Depth gauge rods can be variably positioned with selected ones
of their respective numerals indexed against the edge 131 of the
secondary carriage. They are held in set or adjusted position by a
depth gauge clamp 132 screwed into the carriage to force the
various depth gauge rods against each other. The rods either are of
appropriate width or have intervening spacers, so that they
maintain the proper longitudinal spacing.
To cooperate with the depth gauge rods so provided, there is
mounted on the pillow block 82 a stylus 133 that has a
longitudinally extending surface 134, including inclined side
faces, thereon designed to abut against the end surface 127 of
whatever depth gauge rod happens to be immediately opposite.
In the operation of this device, the various depth gauge rods are
set with an indicated reading similar to that on the key and are
then clamped. The operator then moves the primary and secondary
carriages simultaneously in any desired path so that the stylus 133
has its surface 134 abutted by successive ends of the depth gauge
rods. This produces the various datum surfaces 26, 27, 28, 29 and
30 on the key blank. The operator by moving the primary and
secondary carriages appropriately with respect to the stylus 133
can guide the cutter to produce any of the obtunded profiles
described in FIGS. 1-5, inclusive, and more. When the key blank has
been so configured, the handle 111 is released and the key blank is
removed from the vise. The key blank so configured can subsequently
be utilized as a pattern in a standard key cutting machine of the
sort in which the cutter formulating a new blank is made to follow
the profile of a sample or pattern key appropriately kept in
position.
While the cutter 84 is usually used, I sometimes prefer a higher
speed cutter rotating around a perpendicular axis. As shown in FIG.
7, a high speed gear housing 136 contains a skew driving gear 137
on the end of the shaft 83. Meshing with the gear 137 is a skew
driven gear 138 on the shaft 139 of a cutter 141 of very small
diameter. This cutter 141 is made to cut the key blank in the
manner previously described and does the same kind of job, except
that it leaves small radius curves where sharp intersections would
otherwise be.
* * * * *